@Book{ Betaothe:IngendelConocAspecMetod,
	title = "Ingenier{\'i}a del Conocimiento: Aspectos Metodol{\'o}gicos",
	author = "Amparo Alonso Betanzos and others"
}

@Book{ Boochother,
	title = "El Lenguaje Unificado de Modelado. UML 2.0",
	author = "Booch, Grady and Jacobson, Ivar and Rumbaugh, James",
	publisher = "Pearson Prentice Hall",
	year = "2006",
	isbn = "8478290761"
}

